The invention relates to a process and a device for filling a column with a filler material.
In chromatography so-called separation columns are used. The separation columns are provided with a separation material which is intended to retain selectively the substances contained in a sample. The separation material of the separation columns which are used for example in preparative chromatography are typically silica gels or modified silica gels.
The silica gel which is used typically has a size of a few dozen microns. In order to obtain qualitatively adequate analysis results, it is necessary for the separating medium, for example silica gel, to be homogeneously distributed over the entire length and the entire cross section of the separation column. Separation columns are at present delivered to the user completely packed with the separating medium; the user uses them in a chromatography device. This approach has the disadvantage that as a result of vibrations during transport, a nonuniform distribution of the separating medium in the separation column can occur. Silica gel has particles with different sizes which correspond to a certain size distribution. Vibrations can lead to separation of particles with different grain sizes, so that, for example, larger particles settle to the bottom due to vibrations. The problem of separation during transport can be solved by filling the column with the separating medium directly by the user. JP 08-094603 discloses for example a method with which separation columns for liquid chromatography can be packed. The column is filled by producing a vacuum on one end of the column. The powdered separating medium is sucked into the column by opening a valve. At the same time as intake, knocking occurs. One disadvantage in this arrangement is that nonhomogeneities can occur as a result of feed through a pipeline when the separation column is being filled with the separating material. Moreover the process suggested therein is comparatively complex, since the separation column must be provided on both sides with connections for filling and evacuation. Therefore efficient filling is not possible.